The multi-objective genetic algorithm defined in toolbox of MATLAB software has been employed to optimally design of passive and active models of car-quarter and car-half vehicle. So, by this type of optimization in both the active models, a PID controller has been designed to improve ride comfort.These results show the superiority of the obtained two active suspension models which have been done by this work in comparison with either their presented passive models or those best passive models (2-DOF and 5-DOF) published up to now.